Continuous method of preparing novolaks and devices suitable for such methods



Dec. 22, 1953 H. BLO CONTINUOUS METHOD AND DEVICES SUITA ET AL 2,663,699

EM OF PREPARING NOVOLAKS BLE FOR SUCH METHODS Filed March 4, 1950 HERMAN BLoeM MAR/Mus Sra.

Patented Dec. 22, 1953 NovoLAKs AND DEvIcEs SUITABLE Fon suon MnrHons Herman Bloem and Marinus Stel, Eindhoven, Netherlands, assignors to Hartford `National Bank and Trust Company, Hartford, Conn., as

" .trustee AA'ppucann March 4, 1950, serial No. 1475624 This invention relates-to methods ofpreparing `novolalis from a phenol and a formaldehyde using a catalyst in which the reaction components are continuously supplied to a reaction apparatus and the desired nal condensation product is continuously carried off therefrom. Phenolswhich are suitable are monohydroxybenzene and homologues thereof, such as cresol and xylenol suit able for the purpose, and polyhydricphenols such as resorcinol. As is Well-known, novolaks are phenolformaldehyde Y* condensation products which are not capable of solidifying in themselves.

The object'of the invention is to ensure that gelatinisation cannot occur in such a continuous` preparation -since. otherwise the reaction mixtures becomes insuniciently liquid to be vige orously mixed andtotraverse the reaction ap- 'paratusy If gelatinisation occurs, thisV is probably attributable to lan unduly high'concentration of too high molecular condensation prodthe portions of` the required formaldehyde are supplied simultaneously.V l.This is not strictly necuctswhich may be formed inthe reactionmiin ture in proportion tothe possibilityy of the form- -aldehyde reacting with condensation products already having a fairly high molecular weight instead of with unanectedphenol pr with condensation products having `a small ,-molecular weight. This possibility is not greatin the usual discontinuous method vof preparation and gelatinisation need notocc'urxin the caseef thorough mixing inthe reaction-vessel.

The invention is directedto a method of preparing novolaks from phenol and formaldehyde using a catalyst, all of which are supplied continuously, the desired finalcondensationproduct beling drawn off continuously,y in which the phenol rand the lcatalystare .suppliedtovthe first -ofla plurality of series-connected. reaction chambers and the required amount of formaldehyde is distributed Yover the several rreactionchambers si#- multaneously, the reaction mixture traversing the reaction chambers in?. succession Without gelatinisation of the reaction ymixture occurring yduring the traverse of the several reaction chambers by the reaction mixture. Y

A The invention is preferablyv carried out inf'such manner that a stationary reaction condition preivails in each reaction chamber to .which formaldehyde is supplied.` vSuch stationary reaction conditions occur some time after th'e'initiation of a reaction if the said continuous `supply and discharge Vinvariably take place evenly Iatconstant conditions lof reaction. Furthermore, it is preferable thatthe course Vof the'reaction" conditions should be divided,fullyorsubstantially n part.

essary but thedivisioh of supply and reaction of the formaldehydeover the reaction'vessels must not be so irregular that gelatinisation'would still occur." "y f' o 11 In order to explain-1 the invention more fully, itis observedA that iffphenol, formaldehyde and a catalyst for thepreparation of novolak are continuously'supplied andbrought together in one reaction chamber, there isa great possibility'that thecontinuously supplied formaldehyde may unduly react'with condensationA products already formed, with the described consequenceof undulylhigh concentration of too high molecular condensation products xvIndeed, in such a vcase there'is' a considerable' risk "that f felatinisatioh occurs, unless a smallimolecular-fratio 'between formaldehydeand phenol were chosen,;which would however undulynrestrictthe freedomV of choice in the ratio and hencefof the' possibility of .preparing certain Anovolaks This'is undesirable `for'theprep'arz'ttion of novolaks which are important 'for the lindustrial purposes in which, otherwise, the amountwso'f formaldehydeY 1 used must not be such Jthatigelatinisationiwouldioccur even in the :usualdiscontinuous process.

Furthermore, it is to be noted that the molecular ratio isinfluentialevnif thejinvention is used since the number of reaction chambersover which the'supply'and the reaction of the formaldehyde lmust be divided Tmust be matched to the ratio; Also,` a'division offthe supply and reaction of the formaldehyde `greater` than that which is strictly necessary'for avoiding gelatnis'ation may .a'dd=totl1e'r quality oi" the novolak. The kind of phenol is also of iniluence. When use is made of technical crsol containing from 50% to 55% vby Weight of metacresol, the risk of gelatinisationis greater than'with monoh'ydroxy, benzene, and this factm'ust'be considered by.uti. lising a largefnumbe of vportions of formaldehyde to .be supplied separately. 1

, Additional Yfact-ors which are also influential in carryingoutthe invention are the quantity and vthe ,kind ofthe catalyst, the reaction; temperature, .the sizeof the ,reaction chambers and the ratev ofow V of the l'r'eactionlmixture, which must bechosen to be smaller with a slower reaction in=connection with thequantity and kind oi the catalyst :and/With the reaction tempera-'- ture, sincev itis preferable that'in each reaction chamber theformaldehyde Ysupplied thereto reacts as far ,as possible'or at least for the greater ,In the [fontane it l,has@realy`ben reaction space, local deposition of a condensa-A tion product phase must be avoided,.and.the.re

active mass as a whole must belinalstateoffflow;

As is Well-known, novolaks are, a's a rul,"pr.e. pared from an acid catalyst so that the invention is important more particularlyfforsuch lac`- quers. However, the inventiommayfalsobelutilised if use is made of anlfalkalineatalyst; in-

which event the condensation reaction is slower than with the use of an acid catalyst.

The invention will now be explained by refern ring to the accompanying drawing in whichithe sole ligure is a diagrammatic showing of a series of.r reaction Achambe'rsfor preparing novolaks ac:- cording Ito the invention..

'0f reaction-vessels; I 'to f1';which1are identical with' one another, the :reaction vessel" l in: which a stirrer 8 1 brings 'z about the? required mixing', is

shown in longitudinal section. The other-reas `tion vessels also containza" stirrer:

:If necessary, heatngmay take' placebyl the introduction-of:steam#inttra'doublebottomi. Escaping vapours are condensed in'backflow-cool- `ers2lto 2B. Supply and-'dischargeilines for:cool ing Water are'designatedrfand. 3|;respectively- The .reaction vessels vcommunicatevvvith the 'atmospherefthrough tubesii:

Liquid phenol :and a1 catalyst; solution are caused to ow continuously. from'supplyvessels :Siandi'l into 'the i'lrst'reaction.vessel Linr a ratio ywhich isicontrolledwith the use of cocks .'I2`.and I3; .Atl the samefatimey the amount. of formalineiirequiredtfor: condensation: ilovvsv con= tlrluouslyA fromxthef-suppl'yovessel; I l into: a :distri- 'bution line 32, whencettlre .formalineilisrdistribvutedover the? reaction Vessels: to'l Withxthe v 'use .o'icocksz I5i to' 2| sorthat. feachfiof thenfreaction vvessels receives; simultaneously. 1/7v of. vtheto'tal quantityo'fformalineftolreupplied;

The reactionv mixture continuously iiows from 4the irst f reactiont vessel Il through: an.: overow Stube .-33 :tlo'the secondvessel Zaandisoi on;- so that afterxleaving :thelast'reactionfvessellileatr 3l; .the desirediii'nalcondensation prnductfis'continuoussly obtained. Aftemthezwater has-.been removed', -tlffeinovolakiiseready-formseL Whenfthefcontinuious'fprocessthasproceededvforrsomextinre', erstate of stationary condensation:prevailslineeachfreacL .tion vessel, provided; thatlnixing` atakeszplace intimately.

Examplal An 'installationfo'fthe above-described 'type in which eachi vessel "had a, 'content of2`00cc;, had 'supplied .to itin the manner'nescribedmonohydroxybenzene; formaline' and# a 'solution'of sul;- phuricV acid. The monohydroxybenzene: had 'a contentof v92.5 byvve'ight;tliex'formaline'conf t'alned" 39:6'% by vol. ofii'ormaldehyde and the 'solutionofsulphuri'c 'acid"25%" by weight of sulphuri'c acid. The rateo?supplyoff1;l1e'rnox'lo -liydroxybenzeneiwas-fGZSB mol. or "69'7 ccf per hour, thatfo'fl the formaline-wasf`5i8`3 mol.` lor-442' cc; lp'e'r i liour,` and'tliat yof-"the l'sulpluic:-a'cid 'solution'was '1441.cc. per. Hour.. Consequently; the .first-.reaction chaudiere'-had'ssnppliedtositssk hour flow-ed from the last reaction chamber. Thus, the molecular ratio in which monohydroxy- 'benzene and formaldehyde were supplied was `6;86583=105852 An'aifnointff't of the fformaldeliydeiwas leftinith'e nalreaction product so that mol. ofifformaldehyde per 10 mol. of monohy- Adroxybenzenewas consumed. The temperature was `-98Q A.thefreaction chambers containing ,quickerotatingzstirrers Each chamber contained -113'5 -ccff liquidduring reaction.

The nal condensation product of constant viscositywasnot-carried oi immediately but only Vafterlapse ottime, after which a stationary reaction. .condition has set in in each reaction chamber and the course of the reaction conditionris. raisedeevenly .in the various chambers. It;A is fpossible under sinflilary Yconditions to utilise anapparatus-having. 5 reaction-Vessels Without gelatinsationl occurring.. -IjIoweven the risk of gelatinisation v-increasesin the case of less vthan 5 v`reactionfvessels.

'fhctest installation of Example I had supplied toit in the 'clesc'ribe'd` manner technical cresol having@J contentof vfrom 50% to 55% by weight of .rnetac'zresol,` formaline'and sulphuric acid. The technical cresol hada content. of 98 g. of cresol per cc. dfsolution, the formalne contained 39.6% by vol. offormamhy'de and the sulphuric- Aatestzinstallationsofzthelabbvedescribed kind -halvrngfourre'a'cton".l chambers-had s'u-pplied `to it solutions. off resorcinoL -forlria'line "and caustic.- so'da Alye:v Theiresorcinfrsolution had a-v content 'ofi55:381`g.ofresorciniper'100cm of solution, the `fo'rmaline'contained 38.5%fby`vol.v of formalde- -liyderand'the =caustic'sbda\=lye f contained 2% by IWe'ightofsodiumfhydroxider.

The'rrateoffsupplyofthersorcin solution was flfcc; .iper hourif or 2.0.7A 'mols. 'per hour, that of the* formaline 'wasf92l2 cc; or 1118 "mols. per Vhour, and that of the lye solution was" 441cv. per hour.

' The: molecular' ratioM inwhich.A` 'resorcin and formaldehyde` Were supplied; thus wasA 10:5.71.

The famountiof formaldehyde @left -inthe nal reaction product Was fso fsmallfthatz analysis was notpossiblei.

Y Theftemperatune sthefreaction chambers was 98? C.-

The..four..reactionfchamberse cache-had a con.- tent of..200..cc.f T-heresorcin solutionandthelye .solution.wereintroduoedzinta the rst vessel and ormaline. was. .ir'itroduced` simultaneously into the four reaction chambers. The amounts of formaline supplied to the various chambers were substantially equal (23 cc. per hour).

If in the above-described manner use was made of three reaction chambers, gelatinisation occurred in the third vessel after approximately 4 hours.

If in the above described manner in which use was made of one reaction chamber, gelatinisation occurred within 30 minutes.

While I have thus described my invention with specic examples and applications, other modications thereof will appear obvious to those skilled in the art without departing from the spirit and scope of the invention.

What we claim is:

1. A continuous process for lpreparing novolaks as claimed claim 8 in which a stationary reaction condition prevails in each of the said reaction chambers.

2. A continuous process for preparing novolaks as claimed in claim 8 in which the reaction mixture in each of the said reaction chambers is continuously stirred.

3. A continuous process for preparing novolaks as claimed in claim 8 in which the reaction mixture in each chamber is heated to a temperature of about 98 C.

4. A continuous process for preparing novolaks as claimed in claim 8 in which the phenol is monohydroxybenzene.

5. A continuous process for preparing novolaks as claimed in claim 8 in which the phenol is metacresol.

6. A continuous process for preparing novolaks as claimed in claim 8 in which the phenol is resorcin.

7. A continuous process for preparing novolaks V as claimed in claim 8 in which the catalyser is an acid catalyst.

8. A continuous process for preparing novolaks of the phenol-formaldehyde condensation product type comprising the steps of continuously intro'- ducing into a first reaction vessel a phenol selected from the group consisting of monohydroxybenzene, cresol, xylenol and resorcinol, a catalyst, and formaldehyde in an amount less than that required to completely react the phenol to phenolformaldehyde and suflicient to maintain a stationary reaction condition in said rst vessel, continuously withdrawing from the rst reaction vessel a stream equal in volume to the streams of the reaction components entering the irst reaction vessel, continuously introducing into a second reaction vessel the stream being withdrawn from the rst reaction vessel, introducing a stream of formaldehyde into said second vessel in an amount suiiicient to continue the reaction of the phenol without gelatinizing the reaction mixture, and successively repeating the steps of continuously introducing reaction mixture, adding a quantity of formaldehyde to the reaction mixture to continue the reaction without gelatinization and withdrawing an amount equal in volume to that introduced in succeeding reaction vessels until the reaction is completed.

9. A continuous process for preparing novolaks as claimed in claim 8 in which the quantities of formaldehyde introduced into the first, second and succeeding reaction vessels are substantially equal.

HERMAN BLGEM. MARINUS STEL.

References Cited in the le of this patent Y UNITED STATES PATENTS Number 

3. A CONTINUOUS PROCESS FOR PREPARING NOVOLAKS OF THE PHENOL-FORMALDEHYDE CONDENSATION PRODUCT TYPE COMPRISING THE STEPS OF CONTINUOUSLY INTRODUCING INTO A FIRST REACTION VESSEL A PHENOL SELECTED FROM THE GROUP CONSISTING OF MONOHYDROXYBENZENE, CRESOL, XYLENOL AND RESORCINOL, A CATALYST, AND FORMALDEHYDE IN AN AMOUNT LESS THAN THAT REQUIRED TO COMPLETELY REACT THE PHENOL TO PHENOLFORMALDEHYDE AND SUFFICIENT TO MAINTAIN A STATIONARY REACTION CONDITION IN SAID FIRST VESSEL, CONTINUOUSLY WITHDRAWING FROM THE FIRST REACTION VESSEL A STREAM EQUAL IN VOLUME TO THE STREAMS OF THE REACTION COMPONENTS ENTERING THE FIRST REACTION VESSEL, CONTINUOUSLY INTRODUCING INTO A SECOND REACTION VESSEL THE STREAM BEING WITHDRAWN FROM THE FIRST REACTION VESSEL, INTRODUCING A STREAM OF FORMALDEHYDE INTO SAID SECOND VESSEL IN AN AMOUNT SUFFICIENT TO CONTINUE THE REACTION OF THE PHENOL WITHOUT GELATINIZING THE REACTION MIXTURE, AND SUCCESSIVELY REPEATING THE STEPS OF CONTINUOUSLY INTRODUCING REACTION MIXTURE, ADDING A QUANTITY OF FORMALDEHYDE TO THE REACTION MIXTURE TO CONTINUE THE REACTION WITHOUT GELATINIZATION AND WITHDRAWING AN AMOUNT EQUAL IN VOLUME TO THAT INTRODUCED IN SUCCEEDING REACTION VESSELS UNTIL THE REACTION IS COMPLETED. 